Sliding-test device and method for performing sliding test

Abstract

To provide a sliding-test device and method for performing a sliding test for enabling easy evaluation of the slidability of a desired member under a hydrogen-gas environment.SOLUTION: A sliding-test device 1 includes: a container 3 for storing an electrolytic solution E; an electrode 5 to be immersed in the electrolytic solution E; a first holding unit 4 for holding a first member 10 immersed in the electrolytic solution E, with a sliding surface 10a of the first member 10 being exposed from a liquid surface L of the electrolytic solution E; a second holding unit 6 for holding a second member 20; a voltage application unit 7 for applying a voltage between the electrode 5 and the first member 10 so that the electrode 5 functions as an anode and the first member 10 functions as a cathode; and a driving unit 8 for operating the first holding unit 4 to enable the second member 20 to be slid relative to the sliding surface 10a of the first member 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sliding test machine and a sliding test method. [Background technology]

[0002] Patent Document 1 describes a materials testing machine that performs a materials test by applying a test force to a test piece. The materials testing machine described in Patent Document 1 includes a storage tank that stores a liquid that generates hydrogen through electrolysis, a support mechanism that supports the test piece while the test piece is immersed in the liquid, and a current applying mechanism that applies a current to the liquid while a test force is applied to the test piece. In this materials testing machine, the test piece is immersed in a liquid in which hydrogen gas is generated through electrolysis, and the materials test is performed while supplying hydrogen gas to the test piece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-046283 Summary of the Invention [Problem to be solved by the invention]

[0004] In hydrogen engines and the like, components used in the engine may come into contact with hydrogen gas. Therefore, it is desirable to realize a sliding test to evaluate the sliding properties of components in a hydrogen gas environment. One possible method for adding hydrogen gas to components is the cathodic electrolytic hydrogen charging method used in the above-mentioned materials testing machine. However, it is difficult to conduct a sliding test using this method, in which the entire component is immersed in an electrolyte.

[0005] An object of the present invention is to provide a sliding tester and a sliding test method that can easily evaluate the sliding properties of a desired member in a hydrogen gas environment. [Means for solving the problem]

[0006] The sliding tester of the present invention is [1] "a sliding tester comprising: a container for storing an electrolyte; an electrode immersed in the electrolyte; a first holding unit that holds a first member immersed in the electrolyte with the sliding surface of the first member exposed above the surface of the electrolyte; a second holding unit that holds a second member; a voltage application unit that applies a voltage between the electrode and the first member so that the electrode functions as an anode and the first member functions as a cathode; and a drive unit that operates at least one of the first holding unit and the second holding unit so that the second member slides against the sliding surface of the first member."

[0007] In the sliding tester described in [1] above, the first holding unit holds the first member immersed in the electrolyte in a state in which the sliding surface of the first member is exposed above the surface of the electrolyte. This allows the second member to easily slide against the sliding surface of the first member. Furthermore, the voltage application unit applies a voltage between the electrode and the first member so that the electrode functions as an anode and the first member functions as a cathode. This allows hydrogen gas generated on the first member side to reach the sliding surface of the first member. In this state, the drive unit operates at least one of the first holding unit and the second holding unit, allowing the second member to slide against the sliding surface of the first member in a hydrogen gas environment. Therefore, the sliding tester described in [1] above makes it possible to easily evaluate the sliding properties of a desired member in a hydrogen gas environment.

[0008] The sliding tester of the present invention may be [2] "the sliding tester according to the above [1], wherein the first holding part includes a lid that covers the opening of the container, and the lid has a through-hole that exposes the sliding surface to the outside." The sliding tester according to [2] can prevent the electrolyte from overflowing from the container while a sliding test is being performed. In addition, the second member can be easily slid against the sliding surface of the first member via the through-hole of the lid.

[0009] The sliding tester of the present invention may be [3] "the sliding tester according to the above [1] or [2], wherein the first holding part includes a support pillar provided on the bottom surface of the container, and the support pillar has a mounting surface on which the first member is placed." According to the sliding tester according to [3], the first holding part can stably hold the first member. Therefore, the second member can be stably slid against the sliding surface of the first member.

[0010] The sliding test method of the present invention is [4] "a sliding test method comprising the steps of: preparing a container that stores an electrolyte solution and an electrode immersed in the electrolyte solution; and holding a first member immersed in the electrolyte solution in a state in which the sliding surface of the first member is exposed from the surface of the electrolyte solution; and operating at least one of the first member and the second member so that the second member slides against the sliding surface of the first member while applying a voltage between the electrode and the first member so that the electrode functions as an anode and the first member functions as a cathode."

[0011] According to the sliding test method described in [4] above, for the same reasons as in the sliding tester described above, the sliding properties of a desired member in a hydrogen gas environment can be easily evaluated. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a sliding tester and a sliding test method that can easily evaluate the sliding properties of a desired member in a hydrogen gas environment. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view of a sliding tester according to an embodiment. [Figure 2] 1 is a flowchart of a sliding test method according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and duplicated explanations will be omitted. [Configuration of sliding tester]

[0015] As shown in FIG. 1 , the sliding tester 1 includes a stage 2, a container 3, a first holding unit 4, an electrode 5, a second holding unit 6, a voltage application unit 7, and a drive unit 8. The sliding tester 1 is a tester for evaluating the sliding properties between a first member 10 and a second member 20. The sliding tester 1 measures, for example, the coefficient of friction between the first member 10 and the second member 20 and the amount of wear of the first member 10 and the second member 20 by bringing the second member 20 into contact with the first member 10 and causing them to slide against each other. Hereinafter, the direction in which the first member 10 and the second member 20 slide against each other is referred to as a first direction D1, and the direction perpendicular to the first direction D1 is referred to as a second direction D2. In this embodiment, the first direction D1 is a horizontal direction, and the second direction D2 is a vertical direction.

[0016] The stage 2 supports the container 3. The stage 2 is moved along a first direction D1 by a driving unit 8. For example, the driving unit 8 moves the stage 2 back and forth along the first direction D1. The driving unit 8 is configured by, for example, a motor, gears, etc.

[0017] The container 3 is a container for storing the electrolytic solution E and has an opening 3a. The electrolytic solution E generates hydrogen gas by electrolysis. The electrolytic solution E may be an acidic electrolytic solution such as an H2SO4 (sulfuric acid) aqueous solution, or an alkaline electrolytic solution such as an NaOH (sodium hydroxide) aqueous solution. In this embodiment, the liquid surface L of the electrolytic solution E is a plane parallel to the first direction D1.

[0018] In the sliding tester 1, the container 3 has a bottom wall 31, a side wall 32, and a flange 33. The side wall 32 is formed in a cylindrical shape with the second direction D2 as its height direction. The opening 3a is defined by one end (the upper end in this embodiment) of the side wall 32 in the second direction D2. The bottom wall 31 closes the other end (the lower end in this embodiment) of the side wall 32 in the second direction D2. The flange 33 is formed outward at the other end of the side wall 32 in the second direction D2. The container 3 is made of, for example, an electrically insulating material. As an example, the container 3 is formed in a cylindrical shape with a bottom from a resin material such as polyethylene. The opening 3a is widened by a widened portion 3b on the opposite side of the bottom wall 31 in the second direction D2. The electrolyte E is stored in the container 3 so that the liquid level L is flush with the bottom surface of the widened portion 3b in the second direction D2. The flange 33 is fixed to the stage 2 by bolts or the like (not shown).

[0019] The first holding unit 4 holds the first member 10, which is immersed in the electrolyte E, in a state in which the sliding surface 10a of the first member 10 is exposed above the liquid surface L of the electrolyte E. In this embodiment, the sliding surface 10a is a surface parallel to the liquid surface L. The first holding unit 4 includes a lid 41 and a support 42.

[0020] The lid body 41 is a member that covers the opening 3a of the container 3. The lid body 41 is formed in a plate shape with the second direction D2 as its thickness direction. The material of the lid body 41 is, for example, an electrically insulating material. As an example, the lid body 41 is formed in a disk shape from a resin material such as polyethylene. The lid body 41 is disposed within the widened portion 3b in contact with the bottom surface of the widened portion 3b, and is fixed to the side wall 32 by bolts or the like (not shown). By being disposed within the widened portion 3b, movement of the lid body 41 in the first direction D1 and movement toward the bottom wall 31 in the second direction D2 are restricted.

[0021] The lid 41 has a through-hole 41a that exposes the sliding surface 10a to the outside. The through-hole 41a penetrates the lid 41 along the second direction D2. The through-hole 41a is formed, for example, in a circular shape when viewed from the second direction D2. The through-hole 41a is widened at a widened portion 41b on the bottom wall 31 side in the second direction D2. A portion 11 of the first member 10 having the sliding surface 10a is disposed within the widened portion 41b while contacting the bottom surface of the widened portion 41b. The portion 11 may be fixed to the bottom surface of the widened portion 41b with, for example, an adhesive, tape, or the like. By disposing the portion 11 within the widened portion 41b, movement of the first member 10 in the first direction D1 and movement toward the opposite side of the bottom wall 31 in the second direction D2 are restricted. The liquid level L of the electrolyte E reaches the inner surface of the lid 41 but does not reach the through-hole 41a. That is, a portion 11 of the first member 10 is not immersed in the electrolytic solution E, and the other portion of the first member 10 is immersed in the electrolytic solution E.

[0022] The container 3 and the lid 41 may each be made of a conductive material. In this case, in order to suppress adverse effects on electrolysis, it is preferable that the electrode 5 and the first member 10, which will be described later, are each electrically insulated from the lid 41 by an O-ring or the like, and that the container 3 is electrically insulated from the stage 2.

[0023] The support pillar 42 is a member that supports the first member 10. The support pillar 42 is formed in a columnar shape with the second direction D2 as its height direction. The material of the support pillar 42 is, for example, an electrically insulating material. As an example, the support pillar 42 is formed in a cylindrical shape from a resin material such as polyethylene. The support pillar 42 is provided on the bottom surface 31a of the bottom wall 31 and extends along the second direction D2. The support pillar 42 is formed integrally with the bottom wall 31. The support pillar 42 may also be formed separately from the bottom wall 31.

[0024] The support 42 has a mounting surface 42a on which the first member 10 is placed. The mounting surface 42a is one end surface (the upper end surface in this embodiment) of the support 42 in the second direction D2, and is in contact with the surface of the first member 10 opposite the sliding surface 10a. When the first member 10 is placed on the mounting surface 42a of the support 42, movement of the first member 10 toward the bottom wall 31 in the second direction D2 is restricted. In other words, when the first member 10 is sandwiched between the mounting surface 42a of the support 42 and the bottom surface of the widened portion 41b, downward movement of the first member 10 in the second direction D2 is restricted.

[0025] In the second direction D2, the placement surface 42a is located closer to the bottom wall 31 than the liquid level L. That is, the entire support 42 is immersed in the electrolyte E. In the second direction D2, the sliding surface 10a is located on the opposite side of the bottom wall 31 than the liquid level L. That is, the sliding surface 10a is not immersed in the electrolyte E, and the electrolyte E does not adhere to the sliding surface 10a.

[0026] The electrode 5 is made of a conductive material and functions as an anode in the sliding tester 1. The electrode 5 is made of a metal material such as platinum or copper. On the other hand, the first member 10 is made of a conductive material and functions as a cathode in the sliding tester 1. The first member 10 is made of a metal material such as cast iron or stainless steel. The first member 10 is, for example, a liner material used to fill gaps between members that occur when assembling a hydrogen engine or the like. The material of the first member 10 may be a mixed material containing a conductive material and a resin material, as long as the first member 10 is conductive.

[0027] The electrode 5 is immersed in the electrolytic solution E while being inserted into a slit 41c formed in the lid 41. The slit 41c penetrates the lid 41. When viewed from the second direction D2, the shape of the slit 41c substantially matches the shape of the electrode 5. In this embodiment, the electrode 5 is formed in a plate shape (for example, a rectangular plate shape) having a main surface facing the first member 10 side. This increases the surface area of ​​the electrode 5 facing the first member 10 side, allowing the electrolytic solution E to be electrolyzed efficiently.

[0028] The second holding unit 6 holds the second member 20. For example, the second holding unit 6 holds the second member 20 by placing the second member 20 in an opening formed in the second holding unit 6. The material of the second holding unit 6 is, for example, an electrically insulating material. As an example, the second holding unit 6 is formed from a resin material such as polyethylene. The material of the second holding unit 6 may be a conductive material as long as the second holding unit 6 is electrically insulated from other members. The second holding unit 6 holds the second member 20 so that the second member 20 faces the sliding surface 10a of the first member 10 in the second direction D2. The second holding unit 6 is disposed above the container 3. The second holding unit 6 is supported by a support mechanism (not shown). The support mechanism adjusts the height of the second holding unit 6 so that the second member 20 contacts the sliding surface 10a.

[0029] The material of the second member 20 is appropriately selected depending on the purpose of the sliding test. The second member 20 is formed of, for example, a metal material such as cast iron or stainless steel. The second member 20 may also be formed of a resin material such as polyethylene, or an inorganic compound material such as ceramics. The second member 20 is, for example, a ring material used to maintain airtightness between a piston and a cylinder liner in a hydrogen engine or the like.

[0030] The voltage application unit 7 applies a voltage between the electrode 5 and the first member 10 so that the electrode 5 functions as an anode and the first member 10 functions as a cathode. The voltage application unit 7 is a DC power supply electrically connected to each of the electrode 5 and the first member 10 via wiring 71.

[0031] In the sliding tester 1 configured as described above, the voltage application unit 7 applies a voltage between the electrode 5 and the first member 10, thereby generating hydrogen gas on the surface of the first member 10 in the electrolyte E. The hydrogen gas diffuses from the surface of the first member 10 through the first member 10 and reaches the sliding surface 10a through the interior of the first member 10. This places the sliding surface 10a in a hydrogen gas environment. The first member 10 is the member through which hydrogen gas is diffused. The amount of hydrogen gas reaching the sliding surface 10a can be adjusted by, for example, adjusting the composition of the electrolyte E and the magnitude of the voltage applied between the electrode 5 and the first member 10. With the second member 20 in contact with the sliding surface 10a, the drive unit 8 operates the stage 2, thereby moving the container 3. At this time, the second holding unit 6 and the second member 20 are not operated. In this embodiment, the driving unit 8 moves the container 3, thereby moving the lid 41, the support 42, and the first member 10. For example, the driving unit 8 moves the lid 41, the support 42, and the first member 10 back and forth along the first direction D1. Note that before the driving unit 8 moves the stage 2, lubricant is applied to the sliding surface 10a. As a result, the second member 20 is caused to slide relative to the sliding surface 10a of the first member 10 in a hydrogen gas environment. [Sliding test method using a sliding tester]

[0032] An example of a sliding test method using a sliding tester 1 will be described with reference to FIGS.

[0033] First, a container 3 storing electrolytic solution E and an electrode 5 immersed in the electrolytic solution E are prepared, and a first member 10 immersed in the electrolytic solution E is held in a state in which a sliding surface 10a of the first member 10 is exposed above the liquid level L of the electrolytic solution E (step S01). In step S01, a portion 11 of the first member 10 is placed within the widened portion 41b of the lid body 41, and the lid body 41 is placed within the widened portion 3b. At this time, the first member 10 is placed on the placing surface 42a of the support 42. As a result, the first member 10 is held by the first holding part 4 in a state in which the sliding surface 10a is exposed above the liquid level L of the electrolytic solution E. With the lid body 41 placed within the widened portion 3b, the electrode 5 is inserted into the slit 41c of the lid body 41, and the electrode 5 is immersed in the electrolytic solution E.

[0034] Next, a voltage is applied between the electrode 5 and the first member 10 so that the electrode 5 functions as an anode and the first member 10 functions as a cathode, and the first member 10 is operated so that the second member 20 slides against the sliding surface 10a of the first member 10 (step S02). In step S02, the voltage application unit 7 applies a voltage between the electrode 5 and the first member 10. Then, the driving unit 8 operates the stage 2, thereby operating the first member 10.

[0035] The above steps S01 and S02 constitute a sliding test method performed using the sliding tester 1. In step S01, the electrode 5 may be immersed in the electrolytic solution E, and then the lid 41 may be placed in the widened portion 3b while the electrode 5 is passing through the slit 41c. In step S02, the step of applying a voltage between the electrode 5 and the first member 10 may be performed before or after the operation of the first member 10, or may be performed simultaneously with the operation of the first member 10. [Action and effect]

[0036] In the sliding tester 1 and the sliding test method (the sliding test method using the sliding tester 1), the first holding unit 4 holds the first member 10 immersed in the electrolyte E in a state in which the sliding surface 10a of the first member 10 is exposed above the liquid surface L of the electrolyte E. This allows the second member 20 to easily slide against the sliding surface 10a of the first member 10. Furthermore, the voltage application unit 7 applies a voltage between the electrode 5 and the first member 10 so that the electrode 5 functions as an anode and the first member 10 functions as a cathode. This allows hydrogen gas generated on the first member 10 side to reach the sliding surface 10a of the first member 10. In this state, the drive unit 8 operates the first holding unit 4, thereby allowing the second member 20 to slide against the sliding surface 10a of the first member 10 in a hydrogen gas environment. Therefore, the sliding tester 1 and the sliding test method make it possible to easily evaluate the slidability of a desired member in a hydrogen gas environment.

[0037] In the sliding tester 1 and the sliding test method, the first member 10 functions as a cathode, thereby preventing corrosion of the first member 10. Furthermore, in the sliding tester 1 and the sliding test method, the sliding surface 10a of the first member 10 is exposed above the liquid level L of the electrolyte E, so the sliding test can be performed with the sliding surface 10a coated with lubricating oil. Furthermore, in the sliding tester 1 and the sliding test method, the sliding surface 10a can be placed in a hydrogen gas environment without supplying hydrogen gas from an external source. This prevents the hydrogen gas concentration from increasing. This prevents the hydrogen gas from igniting using the lubricating oil as an ignition source.

[0038] In the sliding tester 1, the first holding unit 4 includes a lid 41 that covers the opening 3a of the container 3, and the lid 41 has a through-hole 41a that exposes the sliding surface 10a to the outside. This makes it possible to prevent the electrolyte E from overflowing from the container 3 while the sliding test is being performed. In addition, the second member 20 can be easily slid against the sliding surface 10a of the first member 10 via the through-hole 41a of the lid 41.

[0039] In the sliding tester 1, the first holding part 4 includes a support 42 provided on the bottom surface 31a of the container 3, and the support 42 has a mounting surface 42a on which the first member 10 is placed. This allows the first holding part 4 to stably hold the first member 10. Therefore, the second member 20 can be stably slid against the sliding surface 10a of the first member 10. [Variations]

[0040] The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the driver 8 reciprocates the first holder 4. However, the driver 8 may reciprocate the second holder 6, thereby reciprocating the second member 20. In this case, the first holder 4 and the first member 10 do not have to be reciprocated. Alternatively, the driver 8 may reciprocate both the first holder 4 and the second holder 6 so that the movement direction of the first holder 4 and the movement direction of the second holder 6 are opposite to each other. The driver 8 may operate at least one of the first holder 4 and the second holder 6 so that the first member 10 and the second member 20 slide relative to each other. For example, the driver 8 may rotate at least one of the first holder 4 and the second holder 6.

[0041] In the above embodiment, the cover 41 and the support posts 42 hold the first member 10, but only the cover 41 may hold the first member 10. Alternatively, only the support posts 42 may hold the first member 10. In this case, the first member 10 may be placed in an opening that opens in the placement surface 42a.

[0042] In the above embodiment, the through-hole 41a of the lid 41 is widened at the widened portion 41b, but the through-hole 41a does not have to be widened. In this case, the first member 10 may be fixed to the inner surface of the lid 41 or the mounting surface 42a of the support 42. The first member 10 may be fixed to the inner surface of the lid 41 or the mounting surface 42a of the support 42 by, for example, adhesive, tape, screws, or the like.

[0043] In the above embodiment, the liquid level L reaches the inner surface of the lid body 41, but as long as at least a portion of the first member 10 is immersed in the electrolyte E, the liquid level L does not have to reach the inner surface of the lid body 41. For example, the liquid level L may be located between the placement surface 42a and the sliding surface 10a or the inner surface of the lid body 41 in the second direction D2. [Explanation of symbols]

[0044] 1...sliding tester, 2...stage, 3...container, 3a...opening, 4...first holding part, 5...electrode, 6...second holding part, 7...voltage application part, 8...driving part, 10...first member, 10a...sliding surface, 20...second member, 31a...bottom surface, 41...lid body, 41a...through hole, 42...support, 42a...mounting surface, E...electrolyte, L...liquid level.

Claims

1. a container for storing an electrolyte; an electrode immersed in the electrolyte; a first holding portion that holds the first member immersed in the electrolytic solution in a state in which a sliding surface of the first member is exposed above the liquid surface of the electrolytic solution; a second holding portion that holds the second member; a voltage application unit that applies a voltage between the electrode and the first member so that the electrode functions as an anode and the first member functions as a cathode; a drive unit that operates at least one of the first holding unit and the second holding unit so that the second member is slid against the sliding surface of the first member.

2. the first holding portion includes a lid that covers an opening of the container, The sliding tester according to claim 1 , wherein the cover has a through-hole that exposes the sliding surface to the outside.

3. the first holding portion includes a support provided on a bottom surface of the container, The sliding tester according to claim 1 or 2, wherein the support has a mounting surface on which the first member is placed.

4. a step of preparing a container storing an electrolytic solution and an electrode immersed in the electrolytic solution, and holding a first member immersed in the electrolytic solution in a state in which a sliding surface of the first member is exposed above the liquid surface of the electrolytic solution; and operating at least one of the first member and the second member so that the second member is slid against the sliding surface of the first member while applying a voltage between the electrode and the first member so that the electrode functions as an anode and the first member functions as a cathode.

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